Who predicted the result correctly?

I spent most of yesterday compiling all the election predictions made by various pundits and pollsters with a view to writing a blog today announcing the winner. But there's no winner. If the Tories end up with 307, as the exit poll predicted, PoliticsHome.com wins points for coming up with the same number, but they overestimated the number of seats the Lib Dems would win at 82. In this, they weren't alone, obviously. Nate Silver of FiveThirtyEight.com predicted the Lib Dems would win 99 and Peter Kellner thought they'd win between 75 and 85. UNS seat calculators, such as Electoral Calculus, also overestimated the number of Lib Dems gains, giving them 66 on the basis of a 22.9% share of the vote.

Of the pollsters, the most accurate were Ipsos MORI and Harris, both of whom predicted the Tories would get 36% of the vote and Labour 29%, but they too overestimated the share the Lib Dems would poll, both imagining they'd get 27%. No pollster had them getting less than that, and Angus Reid and TNS BMRB had them on a whopping 29%. The only pollster who got it absolutely spot on was YouGov, who had the Lib Dems on 24%. Unfortunately, that was on May 4 and by May 5 they put the Lib Dems back on 28%. Like everyone else, I wrong dismissed the May 4 poll as an "outlier".

So what happened? Why did everybody get it so wrong? The clue was provided by Ipsos MORI's marginals poll for the Standard on April 21 which discovered just how "soft" the Lib Dem surge was. Almost all the support for the Lib Dems, it found, came from people who were either undecided, not intending to vote or who were intending to vote for “Others”. Virtually none of if came from people previously intending to vote Labour or Conservative. On the day, it seems, those people who were enthused by Nick Clegg's performance in the first debate simply didn't bother to vote. The lower-than-predicted turn out suggests this, too.

It looks nearly certain that David Cameron will be the next Prime Minister. But one pundit who deserves some credit is The New Statesman's James Macintyre who came up with what, until now, I regarded as the election's most eccentric prediction. He wrote:

I predict that David Cameron, having failed to convince an intelligent electorate that he has fundamentally changed his party, will fail to form a government this week and will never be prime minister.

Instead, I believe that Labour will retain office, almost certainly in a coalition with the Liberal Democrats after the two naturally-allied parties gain more seats and more votes than the Conservatives.

At the time of writing, it's impossible to rule this scenario out – and I stand ready with a dozen molotov cocktails to hurl at Number 10 Downing Street if Gordon Brown refuses to leave. But it does look extremely unlikely.